Chromodoris willani with commensal shrimp Periclimenes imperator ‘on board’. The regular host of this shrimp is Hexabranchus sanguineus, where it is very well camouflaged, but it often lives on other nudibranchs where it is very conspicuous.

Apparently Chromodoris lochi and Chromodoris dianae have different number and shape of gills but this isn't always easy to notice by laymen. The 'easier' external characteristic differences to spot are as follows:

Chromodoris boucheti has yellow tipped rhinophores, but with a special pattern in the yellow tipped gills: there is a vertical black line in the middle of each gill running from the base up. The mantle of Chromodoris boucheti is uniformly colored and smooth looking, without any white specks.

Chromodoris lochi has a rather elongated body of the Hypselodoris genus. It has pink or yellow tinted rhinophores and gills which are sometimes translucent (but with no white dots like in Chromodoris willani). The mantle of Chromodoris lochi is uniformly colored and smooth looking, without any white specks. Its dark/black elongate band in the mantle is thin and unbroken.

Chromodoris dianae also has pale blue based gills and rhinophores, with orange yellow or deep yellow tips, but has more of an oval body form of true Chromodoris genus. Its mantle has white specks or dots hence not smooth looking. The black band in Chromodoris dianae are thicker and discontinuous, especially around the rhinophores.